// Copyright 2016 The Draco Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
#ifndef DRACO_MESH_MESH_IO_H_
#define DRACO_MESH_MESH_IO_H_

#include "draco/compression/config/compression_shared.h"
#include "draco/compression/decode.h"
#include "draco/compression/expert_encode.h"

namespace draco {

template <typename OutStreamT>
OutStreamT WriteMeshIntoStream(const Mesh *mesh, OutStreamT &&os,
                               MeshEncoderMethod method,
                               const EncoderOptions &options) {
    EncoderBuffer buffer;
    EncoderOptions local_options = options;
    ExpertEncoder encoder(*mesh);
    encoder.Reset(local_options);
    encoder.SetEncodingMethod(method);
    if (!encoder.EncodeToBuffer(&buffer).ok()) {
        os.setstate(std::ios_base::badbit);
        return os;
    }

    os.write(static_cast<const char *>(buffer.data()), buffer.size());

    return os;
}

template <typename OutStreamT>
OutStreamT WriteMeshIntoStream(const Mesh *mesh, OutStreamT &&os,
                               MeshEncoderMethod method) {
    const EncoderOptions options = EncoderOptions::CreateDefaultOptions();
    return WriteMeshIntoStream(mesh, os, method, options);
}

template <typename OutStreamT>
OutStreamT &WriteMeshIntoStream(const Mesh *mesh, OutStreamT &&os) {
    return WriteMeshIntoStream(mesh, os, MESH_EDGEBREAKER_ENCODING);
}

template <typename InStreamT>
InStreamT &ReadMeshFromStream(std::unique_ptr<Mesh> *mesh, InStreamT &&is) {
    // Determine size of stream and write into a vector
    const auto start_pos = is.tellg();
    is.seekg(0, std::ios::end);
    const std::streampos is_size = is.tellg() - start_pos;
    is.seekg(start_pos);
    std::vector<char> data(is_size);
    is.read(&data[0], is_size);

    // Create a mesh from that data.
    DecoderBuffer buffer;
    buffer.Init(&data[0], data.size());
    Decoder decoder;
    auto statusor = decoder.DecodeMeshFromBuffer(&buffer);
    *mesh = std::move(statusor).value();
    if (!statusor.ok() || *mesh == nullptr) {
        is.setstate(std::ios_base::badbit);
    }

    return is;
}

// Reads a mesh from a file. The function automatically chooses the correct
// decoder based on the extension of the files. Currently, .obj and .ply files
// are supported. Other file extensions are processed by the default
// draco::MeshDecoder.
// Returns nullptr with an error status if the decoding failed.
StatusOr<std::unique_ptr<Mesh>> ReadMeshFromFile(const std::string &file_name);

// Reads a mesh from a file. The function does the same thing as the previous
// one except using metadata to encode additional information when
// |use_metadata| is set to true.
// Returns nullptr with an error status if the decoding failed.
StatusOr<std::unique_ptr<Mesh>> ReadMeshFromFile(const std::string &file_name,
                             bool use_metadata);

}  // namespace draco

#endif  // DRACO_MESH_MESH_IO_H_
